Ear protector



Sept. 8, 1959 c s EIAL 2,902,692

EAR PROTECTOR 2 Sheets-Sheet 1 Filed Oct. 1, 1953 INVENTORS RALPH L. CHR/sr DAV/D M. CLARK R. L. CHRISTY EI'AL Sept. 8, 1959 EAR PROTECTOR 2 Sheets-Sheet 2 Filed Oct. 1, 1953 JNVENTORS RALPH L. CHRIST)? Dgyo M. CLARK m4 United States Patent EAR PROTECTOR Ralph L. Christy, Silver Spring, MIL, and David M. gar? Worcester, Mass; said Christy assignor to said Application October 1, 1953, Serial No. 383,491

2 Claims. (Cl. 2-3) This invention relates to new and improved acoustical ear protectors. The problem of protecting personnel against noise has beengiven some attention in the past and it has come to be realized that actual physiological and psychological damage, temporary or permanent, results from exposure to noise.

It has been found particularly that workers in close association with jet aircraft engines are greatly affected and the problem is greater and less easily controlled in this hazard than in other health and safety problems. The problem also is associated with exposure to both audible and inaudible sound wave ranges and while the problem is encountered in flight, it is most acute for those invention is not limited to protection against any particular type of noise, but rather is directed to the solution ofthe problem of protection against any kind of noises, although one of the objects of the invention is to provide protection against noises of high frequency while, at the same'time, providing some measure of admission of low sounds of lower frequencies, such as the human voice.

It has been found that symptoms such as headache, nausea, dizziness, loss of hearing, vertigo and gastrointestinal discomfort have been found to exist particularly with those associated with jet engines and the termfultrasonic sickness has been used in some cases to classify these effects of exposure. The effects of exposureto noise are produced essentially upon or through the hearing mechanism and the physiological effects may be-more serious with exposure to noise from jet engines. With increase in power of engines, the noise is bound to likewise increase, and acoustical engineering efforts in all probability will never eliminate the noise at its source, so that the prime consideration, particularly in this invention, deals with the protection of the ears of the individuahand it has been found that the protection against the sound waves also allows the construction of devices which protect against physical blows or injuries in falling also, so that the ear is protected in two ways. Ear plugs have been found not only to be very dangerous in the liability of being lodged in or blown into the ear canal, but these plugs are largely ineffective because a large part of the sound waves are conducted through the bones of the skull adjacent the ear canal.

Another of the objects of the present invention resides in the provision of an ear protector which does not touch any part of the ear at all, does not press upon the .6211 orv upon the ear canal, and provides the utmost in COiitfort as well as protection. Furthermore, ear plugs andany devices which touch the ear or apply pressure to the ear are not sanitary and requires meticulous hygienic and other maintenance practices.

. The present invention is also applicable generally to industry as hydraulic presses, high speed wood planers, riveting, guns, certain kinds of cutting, etc., produce high level noise often injurious in the ways outlined above and it has been found that time is lost from the job by reason of sickness induced by high level noise, and many States are anticipating setting a limit to noise in factories alone, which protection must be afforded to the workers.

Other objects and advantages of this invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 is a view in front elevation, partly in section, illustrating a form of novel ear protector;

Fig. 2 is a view in side elevation;

Fig. 3 is a view in rear elevation thereof;

Fig. 4 is a view in front elevation on an enlarged scale of one of the ear protector devices;

Fig. 5 is a view in side elevation thereof;

Fig. 6 is a top plan view;

Fig. 7 is a transverse section thereof on an enlarged scale;

Fig. 8 is a longitudinal section therethrough on an enlarged scale;

Fig. 9 is a plan view on an enlarged scale of a modified device;

Fig. 10 is a longitudinal section therethrough; and Fig. 11 is a longitudinal section through a modification. In carrying out the present invention, a uniformly adjustable helmet is provided as shown in Figs. 1, 2 and 3. This helmet comprises fabric side pieces 10 and 12 which are connected by a top and rear section generally indicated at 14 and shaped as shown in these figures to conform in general to the shape of the head. Longitudinally and centrally of the piece 14 there may be provided an adjustable lace 16 which if present is usable to tighten the helmet throughout to make it conform to different sizes of heads. The helmet encloses the entire head except for the face and comes down to the nape of the neck, see the numeral 18.

The front portion of the helmet is left open for the face of the wearer to be exposed. Centrally of the side portions 10 and 12, there are oval cut-out portions generally indicated at 20 in dotted lines, as best shown in Fig. 2, and these cut-outs are closed by outwardly protruding ear protector holder devices which comprise fabric oval parts 22 to which are sewed annular fabric members 24, the latter being in turn sewed to the side pieces 10 and 12, closing the oval openings therein.

It will be seen that the holders 22, 24 protrude outwardly and that the same may be slightly tapered. That is, the piece 22 is not quite as large as the corresponding hole in the respective side pieces 10 or 12 and the reason for this taper is that the holders 22, 24 are particularly constructed for removability of the ear protector itself, holding the ear protector as, for instance, by a light frictional contact therewith. However, snap fasteners 25 may also be used to provide a more positive fastener. The ear protector devices are alike for each side of the head and may be transposed. These protectors are oval in shape and do not have any particular top or bottom edge, so that any protector may be inserted in any receptacle or holder, and it will be held therein.

Each ear protector comprises an oval dish-shaped element generally indicated at 26. This element is deeply concaved at 28 and provides a complete upstanding rim 30. This rim is made tapering and concave at its edges, from the outer circumference inwardly thereof, as clearly shown in Figs. 7 and 8, and the outer circumference is curved or rounded off as at 32. The material of these members is preferably a cellular cellulosic acoustical material which is extreme lightweight and fairly rigid and as an example, a cellular cellulose acetate has been found to be acceptable for the purpose.

Cemented or otherwise secured to the concave rim of the flange 30, there is provided a soft, deformable lightweight sound deadening oval ring generally indicated at 34 and this may be made of, for instance, a serrated latex sponge rubber or similar material which is soft and pleasant to the touch, which is formable to the skull bones surrounding the ear and which is easily cemented as described. It is preferred that the oval ring 34 extend down along the outside edges of the more rigid dished member 26, as at 36, as this elongates the joint and provides against sharp corners so that the sound wave barring properties of the combined members 26 and 34 are improved.

If desired, small dents or recesses 38 may be applied to the surfaces of the member 26 to increase the sound deadening qualities thereof. The entire device is adapted to be coated with a latex skin 39 or some other material may be used in order to create a member having a uniform sanitary surface which is continuous and tough so that the devices may be easily repeatedly washed without damage.

The ear protectors which are referred to as the removable sound deadening members, shown in Figs. 4 to 11, inclusive, are easily and quickly insertable and removable from the helmet pockets comprising the members 22 and 24, and these pockets closely fit the same and hold them frictionally in position in addition to the snaps 25 so that the helmet, as seen in Figs. 1, 2 and 3, may be carried in the hand or stored away with the ear protectors 26 held therein. Snaps 40 can be used to adjustably secure the strap 42. Of course, with the device on the head, the ear protectors are held closely against the sides of the head with the soft portions 34 closely pressed to the bony structure surrounding the ear and closely engaging all parts thereof, the ear itself, however, being located in the concaved portions and not being touched at all by any part of the device.

Referring now to Figs. 9, and 11, it is seen that in Fig. 9 the shape of the ear protector device itself is somewhat different from that shown in Figs. 4 and 6, and this shape is of course contemplated as coming within the scope of the invention also.

In this form of the device, the soft rim at 44 is similar to that at 34, but in this case there may be provided a thin, stiff shell 46 at the concave side of the member 48, the latter being substantially the same as the member 26 in Figs. 7 and 8. This shell is provided with a flange 50 which is interposed between the edge 52 of member 48 and the rim 44. This shell may be metallic, such as copper or aluminum, or it may be of any other suitable material, but in any event it is spaced from member 48 by a layer 54 of relatively loose sound-deadening material of which crinkled filamentary nylon or the like has been found to be eflicient. The same material is also used at the exterior surface of shell 46 as at 56 and a skin-like covering as for instance a chamois at 58 retains the material in the position shown in Fig. 10.

Another layer of chamois or other similar material 60 may be utilized exteriorly of the device if desired.

A modification of this construction is shown in Fig. 11 wherein rim 62 again is similar to that at 34 and 44 but in this case it is desired to provide a central continuous flange 64 as well as an outer flange 66 and an inner flange 68. These flanges are utilized to at least partly position inner flanges on an inner stiff shell 70 and an outer stiff shell 72, these flanges being shown at 74 and 76 respectively as lying between the sound-deadening block 78 similar to that at 48 and the soft rubber rim. In this case also, sound-deadening material which is indicated in three separate places at 89 is used somewhat similarly to the disclosure in Fig. 10 to separate the shell from the sounddeadening member 78, in all cases it being desired to separate the rigid shells whether metallic or otherwise, from the sound-deadening material of the main parts of r 4 the device identified as 48 and 54 in Fig. 10 and 73 in Fig. 11.

For certain kinds and modifications of the noise, it has been found that these shells apparently increase the effect of the sound-deadening apparatus in the low wave length ranges of sound and therefore in some cases this shell construction is preferred to the non-metallic constructions of Figs. 7 and 8.

When it is desired to remove the ear protectors for storing them, washing, etc., they are easily removed by the fingers and may be quickly and easily washed with soap and water and either stored away or replaced. This fact alone provides a great advantage over anything in the prior art for hygienic reasons and for ease of manipulation and application. It should be realized that these helmets are ordinarily used in places Where they are issued from a supply depot when they are to be used and, therefore, in most instances a person will not have his own helmet and ear protectors but, instead, they will be issued to him; therefore, sanitation is required and the presentinvention solves this problem completely.

The ear protectors 26 are easily replaced in case of damage to them and the construction is such as to break up sound waves at the outside and to obviate soundboard effect at the inside and in this connection it may be stated that the cellular construction of both parts 26 and 34 may be varied within the limitation of this invention, depending in some cases upon the conditions to be met. That is, a sponge rubber type of material may be used wherein the cells thereof communicate but in some instances more effective protection is obtained by using a material wherein the cells are completely separate and and are independent, such as cellular vinyl sponge.

It will be seen that this invention provides a construction that carries out all the objects of the invention as originally recited and overcomes the problems of the art in a manner clearly distinct and greatly advantageous over the prior art devices.

The ears of the user are not pressed upon but are physically protected; the sound deadening effect -is enhanced; washing and sanitation is made possible for the first time in the art; no vibration is created in the device, so that the user never need hold his hands over the protectors, and the device is comfortable, efiicient and safe.

Having thus described our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what we claim is:

1. An ear protective device comprising a concavoconvex ovate dish-like rigid member of lightweight, nonmetallic cellular material, said member being substantially uniform in section and having an edge flange increasing the concavity of the device, and a soft, cellular lightweight rim secured to the flange and in turn increas ing the concavity of the device, said member having unencumbered surfaces one of which is provided with a series of depressions, said rim having a flat, uni-planar edge to contact the head of the user aboutthe ear. i

2. The device of claim 1 wherein both the inner concave and outer convex surfaces are provided with depressions scattered over the respective surfaces.

and

References Cited in the file of this patent UNITED STATES PATENTS Waldron Feb. 15, 1921 

